Process of manufacturing hollow bodies



Jan. 27, 1942.` v, EHRENHAFT v V PROCESS 0F MANUFACTURING,HOLIIJOW BODIES Filed April' 21, 1959 ww-wrap.-

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Patented Jan. 27, 1942 PROCESS F MANUFACTURING HOLLOW BODIES Viktor Ehrenhaft, Brunn, Czechoslovakia Application April 21, 1939, Serial No. 269,078 In Czechoslovakia. April 23, 1938 Claims.

This invention relates to a process for the manufacture of hollow filling-in bricks for concrete or reinforced concrete ceilings, walls and the like.

Building-slabs made by binding with an adhesive wood-wool, wood libre, wood chips, peat wool or the like have been known. Thereby porous building slabs are formed, which are light, fire-proof, sound absorbing and insulating from heat.

It has now been found possible to produce, from such porous material and a binding agent,

hollow filling-in bricks for concrete or reinforced concrete ceilings, walls and the like, provided certain measures are taken with respect to the formation of the hollow spaces.

f According to the invention, internal pressure is applied to the brick during its formation by a multi-part core, the parts of which, during the pressing process, will move over one another, so that the cross section of the cavity is thereby increased. Beside such internal pressure directed outwardly, an external pressure may be applied to the material by means of a die or the like. Preferably, the core, which during the pressing process lies in the mold, is, after the formation of the brick, replaced by another core that remains within the cavity while the molded brick is hardening.

In the drawing, embodiments of such a device are illustrated by way 0f example.

Figure 1 shows diagrammatically a pressing process in which compression is effected by merely applying an outward pressure to the several parts of the core.

Figure 2 shows such diagrammatical view, in which, beside the outward pressure from inside. another pressurev from outside is applied to the material to be compressed.

Figure 3 shows, diagrammatically, an apparatus for carrying out the process according to Figure 1. Such apparatus, however, when correspondingly modified, is adapted to be utilised for carrying out the process according to Figure 2.

Figure 4 shows a mold with core inserted for the process according to Figure'2 with a core.

applied against the said mold, about which core the molded brick is to harden.

of about in order to exert pressure on the material from which the molded bricks are to be made. According to Figure 2, the four parts 2 of the metal core move in such a manner that the lower parte 2 of this core, in the same way as in Figure l, 'may be moved'outwardly at an angle of 45, while the upper parts 2 of the core are horizontally moved apart. Moreover, external pressure, for example by means of a die, and in the direction of arrow A is applied to the material to be compressed, so that the said material is pressed from both outside and inside.-

The manner in whichl such movement of the core parts 4can be effected, is shown in Figure 5,

of carrying out the pressing process, are rotated' in opposite directions, so that shaft 3 will turn, for example, clock-wise and shaft 4 will turn counterclockwise. It will be seen from Figure 3 that the former rotation is obtained by mounting a hand wheel '5 on the end of shaft 3, and that the opposite rotation of the shaft 4 is eifected by the transmission gear I, 1, toothed wheel 1 being located on shaft 4. As will be seen from Figure 5, short levers I, 9 are mounted on the shafts 3,'4, and pivotally connected to the ends of the levers are crossed tie-rods Il, ll. of which the other ends are pivotally connected to the core-parts 2'. On rotation of the shafts the two core parts 2' which mutually guide each other are moved apart in va horizontal direction.

The movement of the core parts 2 is eifected by further levers I2 and I3 mountedv on .the shafts I and 4 respectively. Rods I4 are pivotally connected to the ends of the levers I2, i3, the rod connected to the lever I3 being omitted from the drawing for the sake of clarity, and the other ends of these rods are coupled to the core parts 2. ,The angular disposition of the levers and rods is such that on rotation of the Figure 5 is a view of the cross section of the shafts the core parts 2 are moved youtwardly at an angle of about 45. y

The co-operating edges of the four core parts are beveiled so that as the core parts move out. wardiy their edges remain in `contact and nov relative movement of the core parts. According to Figure 5 the mold I5 is made of metal, since it has to serve for compression of a material whose binding agent is magnesla cement (Sorel cement), which requires a raised temperature for setting. Hinges I6 are provided by which the mold is opened. The upper part of the mold comprises vertical walls 21, the inner faces whereof serve as guides for a cover Il which by means of a die is forced downward and which, at the beginning of compression, is shown in dotted lines and at the end of compression is shown in full lines.

Operation, in the case where a binding agent which will set at the temperature of the air is used, for example Portland cement, is shown in Figures 3 and 4. In Figure 3 a wooden mold i8 is arranged on a table I9, the walls of which mold are interconnected in a hinge-like manner. On the right hand part of the ligure, that is, at the rear end of the table, the opened wooden mold is shown Into this mold material to be compressed is poured and the mold displaced towards the front end of the table so that the fourpart core mounted on shafts 3, 4, will ybe moved into the interior of the Wooden mold I8 which, when it has been lled with more material, is closed. The wooden mold is reinforced with suitably profiled metal strips 2|, to which metal reinforcement is connected a locking mechanism, which, on the wooden mold being closed, is operated so that such mold will resist intensive internal pressure. Such pressure is effected by turning the hand wheel in the previously described manner causing the expansion of the core parts. Thereupon the core 22 is displaced so as to abut the mold on the left side thereof. The said core, which may be made of wood, will serve to nil exactly the cavity of the molded brick during the subsequent drying process, so that during such drying process no inward swelling of the material can take place.

The purpose of the use of the cores 22 during the drying process is to keep the metal core 20 permanently attached to the machine, such drying process taking a relatively great time, so that during this time,the formation of more molded l bricks would not be possible. The cross section of the core 22 perfectly corresponds to the cross section of the core 20 in its final position, so that it will be possible to shift the mold Il together with the formed brick over the core 22. The replacing core 22I is arranged on the shafts 3, l, which serve as guides for the said core.

In order to facilitate the removal of the core 22 when thebrick has dried the core 2| is formed by boards which are wedge-shaped in plan and trapezoidal in longitudinal section.

During the compression according to Figure 2, which compression is effected from both outside and inside, when a. wooden mold, as shown in Figure 4, is used, and the said mold is to be shifted over the core serving for the drying process, it is necessary, after the pressing process has been carried through, to tightly close the said mold. In order to avoid collapse of the wooden mold during the pressing process, a plurality of loops 23, made for example from U irons or channel section irons, and formed at 2| like hinges, are permanently mounted within the machine. After compression the loops 23 are replaced by loops 25, which also force downward the wooden cover 26 of the mold, on which the die has acted during the pressing process.

What I claim is:

1. A process of manufacturing hollow bodies from porous material containing a binding agent, which consists in placing such material into a mold provided with pressure means therewithin. subjecting said material to pressures from said inner pressure means by slidably expanding the inner pressure means, replacing said inner pressure means by a core filling the hollow space formed by said inner pressure means, during withdrawal of said inner pressure means from said mold, and allowing said material to dry spect to an axis of said body being formed.

3. A process according to claim 1, wherein said pressure produced by said inner pressure means is applied in linear and in a direction angularly thereto.

4. A process according to claim 1, wherein said pressure produced by said inner pressure means is at least partially applied in an angular direction with respect to an axis of said body being formed.

5. A process of manufacturing hollow bodies from porous material containing a binding agent, which consists in placing such material into a mold provided with pressure means therewithin and therewithout, subjecting said material to pressures from said inner pressure means by slidably expanding the inner pressure means while the outer pressure means being applied, replacing said inner pressure means by a core lling the hollow space formed by said inner pressure means, during withdrawal of said inner pressure means from said mold, and allowing said material to dry while s'aid core is therewithin.

VIKTOR EHRENHAFI'. 

